A motorcyclist who suffered life-threatening brain injuries after he crashed during a police pursuit says officers are not to blame - despite a highly critical report.

Dion Batt was chased by police after he was seen riding at more than 100 km/h in a 50km/h zone.

Mr Batt, who had methamphetamine in his system, crashed into a traffic island in Don Buck Rd, Massey, and was hurt so badly he wasn't expected to survive.

Yesterday, the Independent Police Conduct Authority released a report on the 25-minute pursuit in March 2010. It said the chase "lacked adequate command and control and was plagued with communication issues and breaches of policy".

At least 11 patrol cars and the police helicopter were "unnecessarily" pursuing Mr Batt at up to 122km/h. The review found multiple issues, including cars deployed by three different dispatchers and a roadblock set up without authority.

Mr Batt, who now lives with his parents in Raglan, said yesterday that he did not want to speak about the incident other than to say he placed no blame on police for the outcome.

"No one else was to blame. It was my fault," Mr Batt said through his mother, Sharon, because his injuries meant he couldn't be interviewed.

"I realise there was fault on [the police's] part," Mrs Batt said, "but I still as a mother ... put the fault squarely on Dion's shoulders because everything starts from somewhere and that's where it started."

When the incident happened, Mr Batt, a father of three, was living two lives, she said. "There's one of the happy family man and one of the man addicted to methamphetamine."

Her son, a former oil rig worker, had returned home to Raglan to be close to his sons Cameron, 15, and Konrad, 13, and daughter Cyann, 4, and was attempting a reconciliation with their mother.

However, his drug use, which started when he was a teenager, was spiralling downwards, Mrs Batt said.

On the day of the crash, he failed to turn up at a family reunion. Mrs Batt's husband, Peter, then received the call from police they had long feared.

"The reaction was shock, of course, but then also the reaction was, 'It's happened'. It was a matter of when," said Mrs Batt.

Dion Batt was taken to Auckland City Hospital, where his family were told he had no chance of survival.

"It was heart wrenching," Mrs Batt said. "They basically thought Dion had no hope and the machines would be turned off. I think having us at such a volume of people and noise, it obviously triggered something in Dion's brain and his finger started to move."

He was re-scanned and underwent urgent brain surgery.

Mr Batt is now in a wheelchair, looked after by his parents and other carers. His two sons also live with him.

"He's a happy man," Mrs Batt said. "He's got restricted mobility, but he still can take a few steps. His comprehension is slow."

Considering what he went through, his life was basically good, she said. "He and ourselves, we hope that he will one day find a partner and be happy - someone who'll understand and who'll love him."

Assistant Commissioner Allan Boreham said police were working through the authority's seven recommendations, which include amending the fleeing-driver policy relating to ground and air operations, consideration of the type of vehicle the offender is driving and clarifying use of roadblocks.

"If they are not already adopted in there [the fleeing-driver policy], we will be putting them in," he said.

"Most of these, when they occur, our staff are able to follow policy and they are normally resolved without people being hurt. In this case, we haven't got it right ... It's a 100 per cent business - we've got to get it absolutely right."

He said some officers involved in Mr Batt's pursuit had been disciplined.